Cyclists complete a 50-mile ride during the Park-to-Park Bike Ride through Joshua Tree National Park, Calif., April 30, 2016. The event was hosted as a joint effort between the Combat Center, the City of Twentynine Palms and the Joshua Tree National Park Service to celebrate Earth Day as well as the 100-year anniversary of the park. (Official Marine Corps photo by Lance Cpl. Levi Schultz/Released) - Cyclists complete a 50-mile ride during the Park-to-Park Bike Ride through Joshua Tree National Park, Calif., April 30, 2016. The event was hosted as a joint effort between the Combat Center, the City of Twentynine Palms and the Joshua Tree National Park Service to celebrate Earth Day as well as the 100-year anniversary of the park. (Official Marine Corps photo by Lance Cpl. Levi Schultz/Released)